Means for sealing a joint, filling a space and the like

ABSTRACT

The invention concerns a means for sealing joints or the like with a heat expandable sealing compound, the necessary heat being provided by aid of a heat providing means cooperating with the sealing compound. The new and inventive feature resides in the fact that the expanding agent of the sealing compound, when actuated by the heat providing means, generates at least part of the heat necessary to maintain and propagate the expansion of said sealing compound.

United States Patent Forsgren [54] MEANS FOR SEALING A JOINT,

FILLING A SPACE AND THE LIKE [72] Inventor: Kiell Rudolf Forsgren, Orebro, Sweden [73] Assignee: United Shoe Machinery Company AB,

Abyvagen, Orebro, Sweden 22 Filed: May 25,1970

21 Appl.No.: 40,408

[52] U.S. Cl ..277/237 [51] [56] References Cited UNITED STATES PATENTS 3,l25,346 3/1964 Poltorak ..277/34 [151 3,655,213 [451 Apr. 11,1972

FOREIGN PATENTS OR APPLICATIONS 576,206 3/1946 Great Britain ..277/26 Primary Examiner-Robert I. Smith Attorney-Pierce, Scheffler & Parker [51] ABSTRACT 4 Claims, No Drawings MEANS FOR SEALING A JOINT, FILLING A SPACE AND THE LIKE The present invention concerns means for sealing a joint filling a space and the like, comprising a sealing compound and a heat providing means adjacent thereto, said sealing compound containing an expanding agent which, when heated to decomposition, causes expansion of said sealing compound.

A problem generally encountered when expanding plastomers and elastomers, as for instance when an expanding agent contained in the plastic material is decomposed, is that the expanding agent itself generates heat during the decomposition, which heat generation is difficult to control. In the production of objects of foam material the mould is therefore often cooled when the foaming has been initiated and has proceeded for a certain time.

When such foaming or expanding technics are used for sea]- ing joints, filling spaces or the like, it is impossible to control the process by cooling. For the first, the costs therefore would be excessively great, since the sealing is carried out at the mounting site, for instance when a building is erected, and the devices for cooling must, therefore, be transported to said site and set up at each sealing place. For the second, the condition at different sealing places are not the same, so that it will be almost impossible to predetermine the moment for the amount of cooling. On account hereof the method of sealing above referred to has proven comparatively chancy, and a complete charring of the sealing compound has occurred in some cases and resulted in faulty sealing.

The present invention therefore concerns means by aid of which said shortcomings are overcome, and this aim is mainly achieved by the fact that said expanding agent, after having been brought to a local initial decomposition by actuation of said heat providing means, generates at least part of the heat necessary for maintaining said decomposition and for propagating same to the expanding agent contained in adjacent portions of said sealing compound.

According to the invention, no measures such as cooling are undertaken to remove surplus heat developed during the decomposition of the expanding agent; instead the supply of heat for the decomposition from the outside is interrupted or reduced when said decomposition has started, and the heat developed thereby is used to maintain and propagate said decomposition without causing any surplus heat. Since it is possible to determine the quantity of heat developed by the decomposition of an expanding agent, it is also possible to govern the quantity of heat generated during the sealing operation by changing the composition of the expanding agent and/or the proportion of the expanding agent contained in the sealing compound so that said expanding agent by its decomposition delivers all or at least part of the quantity of heat necessary to maintain the decomposition and to propagate same to adjacent portions of the sealing compound.

The interruption or the decrease of the supply of heat from the outside, when the decomposition process has started, also implies that the risk of overheating and charring the sealing compound disappears.

The means according to the invention is preferably formed as a strand which is applied to the joint. Said strand comprises a sealing compound formed to an appropriate profile in which a suitable expanding agent is intermixed to a proportion adapted to the desired expansion. In one or both ends of the strand a cavity is arranged into which the heat providing means, preferably in the form of a pyrotechnical agent, is introduced. When the composition and the amount of the expanding agent is adapted in sucha way, that the quantity of heat developed at the decomposition thereof is sufficient to maintain said decomposition and propagate same through said strand, the amount of pyrotechnical agent needs only to be great enough to initiate a local decomposition at the end or ends of the strand. Said decomposition is thereafter spread along the strand by means of the developed heat so that the desired expansion is provided.

If the expanding agent on the other hand is only capable of developing part of J the quantity of heat required for the decomposition to be maintained and propagated, a passage may be arranged to extend through the strand along the total length thereof, and said passage may be filled with pyrotechnical agent to an amount sufficient for maintaining and propagating the desired decomposition. Since the demand of supply heat is reduced when the decomposition of the expanding agent commences, said pyrotechnical agent can be arranged to form a priming having a great capacity to emit heat at the end or ends of said strand, and to continue through said passage as a portion having a lesser capacity to emit heat. This is preferably achieved by providing a lesser amount of pyrotechnical agent per unit of length in said passage than at the end of said strand. Thereby it is also possible to provide sealing strands having substantially smaller cross dimensions than previously and the consumption of the expensive pyrotechnical agent is diminished. Of course, it is also possible to vary the composition of the pyrotechnical agent in dependence of the additional heat required.

Below are given preferred compositions of the sealing agent and the pyrotechnical agent:

SEALlNG COMPOUND Chloroprene I00 Stearine 7 Zinc oxide 3 Magnesium oxide 2 Phenylbetanaphthylamine 2 Dinitrosopentamethylenetetramine LI 2' Aromatic processoil Amount adapted to desired expansion PYROTECHNICAL AGENT A mixture of ferro-silicon (or iron), pyrolusite, barium nitrate, charcoal, binding agent and water.

What I claim is:

1. Means for sealing a joint, filling a space and the like, comprising a sealing compound formed as an elongated strand and a heat providing means adjacent thereto, said sealing compound containing an expanding agent which, when heated to decomposition, causes expansion of said sealing compound, said expanding agent, after having been brought to a local initial decomposition by actuation of said heat providing means, generating part of the heat necessary to maintain said decomposition and to propagate same to the expanding agent contained in adjacent portions of said sealing compound, said heat providing means being constituted of a pyrotechnical agent provided along said strand of sealing compound in an amount sufficient first to initiate said decomposition, and thereafter to generate the remaining part of said necessary heat.

2. Means as claimed in claim 1 in which said strand of sealing compound has a longitudinal passage, said pyrotechnical agent being arranged in said passage.

3. Means for sealing a joint, filling a space and the like, comprising a sealing compound formed as an elongated strand and heat providing means adjacent thereto, said sealing compound containing an expanding agent which, when heated to decomposition, causes expansion of said sealing compound, said expanding agent, after having been brought to local initial decomposition by actuation of said heat providing means, generating all the heat necessary to maintain said decomposition and to propagate same to the expanding agent in adjacent portions of said sealing agent, said heat providing means being constituted of a pyrotechnical agent provided as a priming at at least one end of said strand of sealing compound in an amount sufficient to initiate said local decomposition.

4. Means for sealing a joint, filling a space and the like, comprising a sealing compound formed as an elongated strand and a heat providing means adjacent thereto, said sealing compound containing an expanding agent which, when heated to decomposition, causes expansion of said sealing compound,

heat providing means being provided in association with said strand of sealing compound in an amount sufficient first to initiate said decomposition, and thereafter to generate at least a substantial part of said necessary heat. 

2. Means as claimed in claim 1 in which said strand of sealing compound has a longitudinal passage, said pyrotechnical agent being arranged in said passage.
 3. Means for sealing a joint, filling a space and the like, comprising a sealing compound formed as an elongated strand and heat providing means adjacent thereto, said sealing compound containing an expanding agent which, when heated to decomposition, causes expansion of said sealing compound, said expanding Agent, after having been brought to local initial decomposition by actuation of said heat providing means, generating all the heat necessary to maintain said decomposition and to propagate same to the expanding agent in adjacent portions of said sealing agent, said heat providing means being constituted of a pyrotechnical agent provided as a priming at at least one end of said strand of sealing compound in an amount sufficient to initiate said local decomposition.
 4. Means for sealing a joint, filling a space and the like, comprising a sealing compound formed as an elongated strand and a heat providing means adjacent thereto, said sealing compound containing an expanding agent which, when heated to decomposition, causes expansion of said sealing compound, said expanding agent, after having been brought to a local initial decomposition by actuation of said heat providing means, generating part of the heat necessary to maintain said decomposition and to propagate same to the expanding agent contained in adjacent portions of said sealing compound, said heat providing means being provided in association with said strand of sealing compound in an amount sufficient first to initiate said decomposition, and thereafter to generate at least a substantial part of said necessary heat. 